The Living World - section B

Question 1

What is an ecosystem

Answer 1

all Biotic (living) and abiotic parts of an area

Question 2

The organisms in a ecosystem are know as producers consumers or decomposes define these terms

Answer 2

Producers - (grass) uses sunlight to produce food
Consumer - a consumer gets energy by eating other organisms (rabbit eating grass)
Decomposer - A organism that gets its energy by breaking down dead material. Bacteria and fungi are decomposes

Question 3

Explain the nutrient cycle

Answer 3

Dead material decomposes releasing its nutrients into the soil. The nutrients in the soil are taken up by plant then eaten by consumers . When the consumer dies the nutrients return to the soil

Question 4

What are the 7 major types of ecosystems

Answer 4

Tundra
Grassland
Boreal forest
Temperature deciduous forest
Polar
Hot desert
Tropical rainforest

Question 5

What is the temp like in a rainforest all year round

Answer 5

It hot all year round between 20-28*c

Question 6

What is the soil like in a rainforest

Answer 6

The soil isn’t very fertile as heavy rain washes nutrients away. There are however surface nutrients due to decayed leafed but this layer is very thin it’s called the humus

Question 7

What is rainforest biodiversity like

Answer 7

Rainforest have very high biodiversity ( Variety of organisms living together both plants and animals

Question 8

What are plants like in the rainforest

Answer 8

Most trees are evergreen to help them take advantage of the continual growing season.
Many trees are really tall and the vegetation cover is dense - very little light reaches the forest floor

Question 9

Give one example on how resinforest are interdependent on each other

Answer 9

The warm and wet climate helps fungi and bacteria in the forest floor to decompose dead plants material rapidly. This make the surface soil high in nutrients, meaning plants can grow rapidly

Question 10

How have humans interfered with rainforest ecosystems

Answer 10

• deformation cause climate change
• trees intercept and takes up lots of water and release it back to the atmosphere providing moisture for further rainfall. Reducing tree may increase the risk f drought. This will affect the plants and animals as they are not suited for this

Question 11

What are the four layers of a rainforest

Answer 11

Shrub layer
Under Canopy
Main canopy
Emergent trees

Question 12

State some adaptions of plant in rainforests

Answer 12

Plants have thick waxy leaves with pointed tips so water can run of it with damaging the leaf
Trees compete for sunlight by growing tall
Climbing plants such as Lianas use tree trunks to reach sunlight

Question 13

State some adaptations of animas in a rainforest

Answer 13

Gliding leap frog - dry thumbs and grip wet thing, eggs made out of water so they don’t dry out and get eaten, webbed feet for gliding
Nocturnal animals e.g sloths so they feed at night when it cooler to preserve their energy
Many animals can swim to help them cross river channels

Question 14

Rainforest experience extremely high deforestation explain reason why

Answer 14

Commercial farming- space to cleared to make room for farms for profit
Commercial logging - cutting down trees to sell and manufacture things for a profit
Mineral extraction
Energy development - hydro dams
Population growth
Road building

Question 15

Why is climate change caused by deforestation

Answer 15

Because trees remove co2 for the atmosphere and when trees are chopped down they also release co2

Question 16

Why is soli erosion caused by deforestation

Answer 16

With less tree canopy to intercept and absorb rainfall more water reaches the soil and washes away the nutrients. Farmers then must destroy more trees to access new land with fertile soil

Question 17

Why are rainforests valuable to people and the environment

Answer 17

• many products e.g. rubber, coffee, chocolate and medicines are sourced from these rainforests. If species become extinct it will be harder to discover new medicines and develop new products
  -Sustainable developments can offer long term economic benefits e.g. ecotourism
  -Protecting the rainforests may reduce the greenhouse effect.
  -some of the impacts of deforestation could affect all countries e.g. climate change
  -Rainforests help regulate climate and the water cycle without them the risks of drought and flooding in certain areas could increase.

Question 18

How can replanting help rainforests be sustainably managed

Answer 18

• new trees are planted to replace the ones that are cut down
  -Its important the replacement tree is the same type as the old tree
  -In some countries their are laws to make logging countries replant trees when they clear a forest

Question 19

How can selective logging help rainforests be sustainably managed

Answer 19

• only some trees are cut down e.g. old ones most trees remain
  -This is less damaging then clearing a whole area. If only a few trees are cut then the forest can still keep its structure, the canopy will remain and the soil will not be exposed. This allows the forest to regenerate.

Question 20

How can ecotourism help rainforests be sustainably managed

Answer 20

• Ecotourism minimises damage to the environment and benefits the local people.
  -Only a small number of visitors are allowed in an area at a time with rules that are imposed to minimise environmental impacts. E.g. waste and litter disposed off properly.
  -Ecotourism provides a source of income for local people, e.g. they act as guides and provide accommodation and transport.
• if local people are involved in ecotourism then they wont need to farm or cut down trees to make money.

Question 21

How can education help rainforests be sustainably managed

Answer 21

-Educating the international community about the impacts of deforestation can encourage people to buy products from sustainable sources
-local people might damage the forest to overcome their poverty without releasing the long-term effects
-educating the local people about the impacts of deforestation can help reduce damage to rainforests
-teaching local people about alternative ways to make money that don’t damage the environment as much, means they wont be dependent on unsustainable options in order to make a living.

Question 22

How can conservation help rainforests be sustainably managed

Answer 22

Many countries have set up national parks and nature reserves within rainforests. in these places damaging activities are banned. However a lack of funds can make it difficult to police these restrictions. As a result some countries have set up funds which oversea governments and business can invest in, in exchange for rainforest land to be reserved.

Question 23

How can reducing debt help rainforests be sustainably managed

Answer 23

Many rainforests are found in LICs that borrow money from wealthier countries. This money must be paid back with interest so these poor countries log farm and mine in the rainforests to make the money back. Reducing debt means countries don’t have to do this and the rainforests can be reserved. However even if the debts are cancelled their is no guarantee that the repayment money will be spent of rainforest conservation. So a better solution is a conservation swap where the debt is cancelled in exchange for a guarantee on conservation

Question 24

How can help rainforests be sustainably managed

Answer 24

there are international agreements in place to try to prevent illegal logging, and to promote the use of hardwood from sustainably managed forests.

Question 25

what is the climate like in deserts

Answer 25

• very little rainfall - less than 250mm per year
  -rainfall patterns vary
  -temps are extreme because of the lack of cloud cover, it can reach 45c but then drop to 0c at night.

Question 26

what is the soil like in deserts

Answer 26

-a lack of leaf fall limits the soils fertility
-little rainfall means the soil often dries out
-soil is often shallow with a gravelly texture

Question 27

what is the plants like in deserts

Answer 27

• due to low rainfall plant growth is sparse, the plants that do now grow such as thorn bushes and cacti, dont need much water
  -plants are usally short e.g. low shrubs or short woody trees, though cacti can grow fairly tall
  -many plants have short life cycles, growing quickly after rain

Question 28

what is the animals like in deserts

Answer 28

-hot deserts contain animals adapted to the harsh environment
-mammals tend to be small and nocturnal e.g. kangaroo rats
-most birds leave the desert during the harshest conditions but some birds, like roadrunners, can live there all year round

Question 29

what is the people like in deserts

Answer 29

-many people living in deserts can grow a few crops near natural water sources, usually in the desert fringes
-indigenous people are often nomadic - they keep travelling to find food and water for their livestock

Question 30

Hot deserts are fragile, interdependent ecosystems

Answer 30

-the biotic and abiotic are all closely related - many of them are dependent on each other
-plants take up nutrients from the soil and provide nutrients and water to the animals who eat them. in turn animals spread the seeds through their dung, helping plants to reproduce.
- the hot and dry climates affect the soil in deserts. Soil are salty due to high evaporation rates, and relatively low in nutrients due to a lack of decompostion of dead plants.

Question 30

Hot deserts are fragile, interdependent ecosystems

Answer 30

-the biotic and abiotic are all closely related - many of them are dependent on each other
-plants take up nutrients from the soil and provide nutrients and water to the animals who eat them. in turn animals spread the seeds through their dung, helping plants to reproduce.
- the hot and dry climates affect the soil in deserts. Soil are salty due to high evaporation rates, and relatively low in nutrients due to a lack of decomposition of dead plants. Therefore plants struggle to grow
- the sparse vegetation limits the amount of food available, so that the desert can only support low-density populations of animals and people.

Question 31

How have plants adapted to live in hot , dry conditions

Answer 31

plants have long roots to reach deep water supplies or they have wide shallow roots to gather as much water as possible when it rains.
Many plants e.g. cacti are succulents. They have large fleshy stems for storing water and thick waxy skin to reduce transpiration.

Question 32

How have animals adapted to hot and dry conditions.

Answer 32

Nocturnal animals stay cool by sleeping in day when the temp is the highest. Many desert animals also have long limbs or ears to give them a bigger surface area to loose heat.
Lots of animals live in underground burrows where temps are less extreme. e.g. tortoise
Some animals store fat that they can break down into water when they need e.g. camel
Adaptations to cope with the sand are common e.g. camels use their triple eyelids, long eyelashes and ability to close their nostrils to keep sand out their eyes and nose.

Question 33

What is desertification

Answer 33

desertification is the degradation of land making it drier and less productive. This occurs when vegetation dies or exposed soil is easily removed by wind or water as their are not roots to hold it together. Nutrients in the soil are lost making it unproductive

Question 34

How does climate change cause desertification

Answer 34

climate change is expected to reduce in areas that are all ready dry. Less rain means less water available for plants to grow so more plants die.
As global temps are increasing more evaporation of water from the ground happens making the soil even drier

Question 35

How has human activities caused desertification

Answer 35

removal of fuel wood - many people in arid areas rely on woods as fuel for cooking but the removal of trees leave soil exposed.
Overgrazing - too many cattle or sheep eat plants faster than they can re-grow. Trampling by animals also erode the soil.
Over - cultivation : if crops are continuously planted in the same areas all the nutrients in the area are used up meaning no more plants can grow their.
Population growth - more people put more pressure on the land leading to even more deforestation, overgrazing and over-cultivation

Question 36

How can water management reduce the risk of desertification

Answer 36

growing crops that need little water e.g. millet or olives can reduce water use. Using drip irrigation on crops instead of surface irrigation means that the soil isn’t eroded by lots of water being added at once.

Question 37

How can tree planting reduce the risk of desertification

Answer 37

trees can be planted to act as windbreaks, reducing wind erosion. Trees can also stabilize the sand and prevent desert from encroaching on farm land. Growing trees amongst crops protect them and the soil by providing shade, reducing temps and evaporation rates.

Question 38

How can soil management reduce the risks of desertification

Answer 38

leaving areas of land to rest in between grazing or planting lets them recover their nutrients. Rotating crops that take different nutrients from the soil prevents the same nutrients from being continually removed. Compost can be used to add extra nutrients to the soil.

Question 39

How does using appropriate technology reduce the risks of desertification

Answer 39

this involves using cheap, sustainable and easily available materials to build things that are easy for local people to maintain. For example, sand fences or terraces can be constructed to stabilise the soil and reduce erosion.